qahw: Add binder support for Audio HAL

- Bring in a new cpp source file which HAL clients talk to
- This code in turn makes the binder proxy/clients side calls
- The binder server calls into the existing qahw.c

Change-Id: I45625bcb2d8a2eb858c68d24f0cad3202d754244
diff --git a/Android.mk b/Android.mk
index e590854..0cfc567 100644
--- a/Android.mk
+++ b/Android.mk
@@ -14,6 +14,7 @@
 include $(MY_LOCAL_PATH)/mm-audio/Android.mk
 include $(MY_LOCAL_PATH)/visualizer/Android.mk
 include $(MY_LOCAL_PATH)/post_proc/Android.mk
+include $(MY_LOCAL_PATH)/qahw/Android.mk
 include $(MY_LOCAL_PATH)/qahw_api/Android.mk
 endif